Andrew Luck was never the standard-operating-procedure football star. He stayed at Stanford, even though he would have been the top pick in the NFL draft. He eschewed endorsement deals in his rookie season, the better to focus on his transition on the field. The former architecture major read books on the history of concrete.

And, occasionally, he let the public see the mental toll the game took on him. At the nadir of his 2017 season -- the one he lost when he overdid his attempts to return from offseason shoulder surgery -- Luck's mood was noticeably dark. A few months later, he was more optimistic about his future, but those few minutes at the end of the 2017 season, when Luck gave a glimpse of the self-doubt that had enveloped him as he struggled with his injured shoulder, was a rare look at a fully self-actualized person and at a fully formed football player. Luck wasn't one for false bravado and he wasn't going to indulge our wishful thinking about what pain does to players in their private moments.

I thought of that scene Saturday night, when the news that Luck will retire at age 29 -- while he stood on the sideline during a preseason game watching his team -- was first reported. Luck has been candid about how much he struggled during that year off, and when you take stock of the injuries he has had in his seven seasons, the idea that he wants to live a different, happier life is pretty easy to understand. In his impromptu press conference Saturday night, Luck called the four-year cycle of injuries and pain and rehabs and returns "unceasing" and "unrelenting," the calf strain that was threatening the start of this season only the most recent thing. The only way he saw out of it was to get out of the National Football League.

"It's taken my joy of this game away," Luck said of the injuries. "I haven't been able to live the life I wanted to live."

Who can fault him for that? The entitled handful of fans who should do some serious self-examination after booing him off the field? Luck gave them his body and -- for long stretches -- his happiness and they thought they deserved more. Luck admitted that it hurt to hear the boos. That embarrassing moment should do nothing but reinforce that Luck made the right decision, that players owe us nothing more than being some entertainment a few hours a week. Luck pulled the curtain back just a bit Saturday night on what players go through the other six days a week to make your Sunday fun and the view was ugly.

Once the shock of Luck's decision wears off -- and the immediate question of where this leaves a playoff-caliber team -- we should appreciate that Luck is the rare person who was true to himself. He admitted that he was resentful of the fun, happy-go-lucky guy Jacoby Brissett was when Luck was dealing with the shoulder injury. He was in a dark place mentally when he tried to play through things before and he said he vowed that if he ever got into that situation again, he would not do it. I wonder how many players will see bits of that news conference and recognize exactly what Luck was talking about. I wonder how many will quietly admire him for his decision. I wonder how many more will wish they had the guts to do it, too.

This, of course, is a staggering setback for the Indianapolis Colts two weeks before the season starts -- and yes, owner Jim Irsay is holding out hope this decision, at age 29, won't be final -- and for the NFL in general. Luck was a phenomenal quarterback. Irsay had mused aloud about winning multiple Super Bowls with him. The promise of his career has not been fully realized, in part, sadly, because he was mismanaged by some of those who were charged with getting the best out of him. The NFL needed more Andrew Luck's, not fewer.

But really, Luck's retirement is a fascinating Rorschach test. There are those who will think Luck is soft for not gritting his teeth again and instead letting the pain drive him from his career. Then there are those who will think Luck is exceptionally strong, to choose happiness over our culture's testosterone-fueled definition of toughness. I know which one I think. And I bet I'd have a lot of company in any locker room.